Research progress on red mud for carbon-containing air pollution control

Red mud (RM) is a strongly alkaline solid waste generated during alumina production, which is increasingly receiving widespread attention because of its great harm to the ecological environment and human. The resource utilization of RM can effectively solve these problems. RM contains various metal oxides and alkaline species that give it great potential for carbon-containing air pollution (CAP) removal, and it is prepared as an adsorbent for CO2 and an oxidation catalyst for CO, CH4, and VCOs. Many studies have been reported on the RM for the degradation of air pollutants, but there is a lack of review on the use of RM for CAP removal. Therefore, this review systematically summarizes the research progress of RM and its modified RM-based materials (MRM) in CAP removal. Firstly, the properties and composition of RM are described, and the effects of different modification methods for RM are elucidated. Then, RM is explored for the sequestration of CO2 and the catalytic oxidation of CH4, VOCs, and CO. The application of MRM is reviewed in CAP removal. Finally, the reaction mechanisms and performance influencing factors of MRM for different CAP are discussed. Furthermore, the outlook and challenges of RM resource utilization for CAP are presented.